1/*
2** $Id: lobject.h,v 2.71.1.2 2014/05/07 14:14:58 roberto Exp $
3** Type definitions for Lua objects
4** See Copyright Notice in lua.h
5*/
6
7
8#ifndef lobject_h
9#define lobject_h
10
11
12#include "llimits.h"
13#include <sys/lua/lua.h>
14
15
16/*
17** Extra tags for non-values
18*/
19#define LUA_TPROTO	LUA_NUMTAGS
20#define LUA_TUPVAL	(LUA_NUMTAGS+1)
21#define LUA_TDEADKEY	(LUA_NUMTAGS+2)
22
23/*
24** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
25*/
26#define LUA_TOTALTAGS	(LUA_TUPVAL+2)
27
28
29/*
30** tags for Tagged Values have the following use of bits:
31** bits 0-3: actual tag (a LUA_T* value)
32** bits 4-5: variant bits
33** bit 6: whether value is collectable
34*/
35
36#define VARBITS		(3 << 4)
37
38
39/*
40** LUA_TFUNCTION variants:
41** 0 - Lua function
42** 1 - light C function
43** 2 - regular C function (closure)
44*/
45
46/* Variant tags for functions */
47#define LUA_TLCL	(LUA_TFUNCTION | (0 << 4))  /* Lua closure */
48#define LUA_TLCF	(LUA_TFUNCTION | (1 << 4))  /* light C function */
49#define LUA_TCCL	(LUA_TFUNCTION | (2 << 4))  /* C closure */
50
51
52/* Variant tags for strings */
53#define LUA_TSHRSTR	(LUA_TSTRING | (0 << 4))  /* short strings */
54#define LUA_TLNGSTR	(LUA_TSTRING | (1 << 4))  /* long strings */
55
56
57/* Bit mark for collectable types */
58#define BIT_ISCOLLECTABLE	(1 << 6)
59
60/* mark a tag as collectable */
61#define ctb(t)			((t) | BIT_ISCOLLECTABLE)
62
63
64/*
65** Union of all collectable objects
66*/
67typedef union GCObject GCObject;
68
69
70/*
71** Common Header for all collectable objects (in macro form, to be
72** included in other objects)
73*/
74#define CommonHeader	GCObject *next; lu_byte tt; lu_byte marked
75
76
77/*
78** Common header in struct form
79*/
80typedef struct GCheader {
81  CommonHeader;
82} GCheader;
83
84
85
86/*
87** Union of all Lua values
88*/
89typedef union Value Value;
90
91
92#define numfield	lua_Number n;    /* numbers */
93
94
95
96/*
97** Tagged Values. This is the basic representation of values in Lua,
98** an actual value plus a tag with its type.
99*/
100
101#define TValuefields	Value value_; int tt_
102
103typedef struct lua_TValue TValue;
104
105
106/* macro defining a nil value */
107#define NILCONSTANT	{NULL}, LUA_TNIL
108
109
110#define val_(o)		((o)->value_)
111#define num_(o)		(val_(o).n)
112
113
114/* raw type tag of a TValue */
115#define rttype(o)	((o)->tt_)
116
117/* tag with no variants (bits 0-3) */
118#define novariant(x)	((x) & 0x0F)
119
120/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
121#define ttype(o)	(rttype(o) & 0x3F)
122
123/* type tag of a TValue with no variants (bits 0-3) */
124#define ttypenv(o)	(novariant(rttype(o)))
125
126
127/* Macros to test type */
128#define checktag(o,t)		(rttype(o) == (t))
129#define checktype(o,t)		(ttypenv(o) == (t))
130#define ttisnumber(o)		checktag((o), LUA_TNUMBER)
131#define ttisnil(o)		checktag((o), LUA_TNIL)
132#define ttisboolean(o)		checktag((o), LUA_TBOOLEAN)
133#define ttislightuserdata(o)	checktag((o), LUA_TLIGHTUSERDATA)
134#define ttisstring(o)		checktype((o), LUA_TSTRING)
135#define ttisshrstring(o)	checktag((o), ctb(LUA_TSHRSTR))
136#define ttislngstring(o)	checktag((o), ctb(LUA_TLNGSTR))
137#define ttistable(o)		checktag((o), ctb(LUA_TTABLE))
138#define ttisfunction(o)		checktype(o, LUA_TFUNCTION)
139#define ttisclosure(o)		((rttype(o) & 0x1F) == LUA_TFUNCTION)
140#define ttisCclosure(o)		checktag((o), ctb(LUA_TCCL))
141#define ttisLclosure(o)		checktag((o), ctb(LUA_TLCL))
142#define ttislcf(o)		checktag((o), LUA_TLCF)
143#define ttisuserdata(o)		checktag((o), ctb(LUA_TUSERDATA))
144#define ttisthread(o)		checktag((o), ctb(LUA_TTHREAD))
145#define ttisdeadkey(o)		checktag((o), LUA_TDEADKEY)
146
147#define ttisequal(o1,o2)	(rttype(o1) == rttype(o2))
148
149/* Macros to access values */
150#define nvalue(o)	check_exp(ttisnumber(o), num_(o))
151#define gcvalue(o)	check_exp(iscollectable(o), val_(o).gc)
152#define pvalue(o)	check_exp(ttislightuserdata(o), val_(o).p)
153#define rawtsvalue(o)	check_exp(ttisstring(o), &val_(o).gc->ts)
154#define tsvalue(o)	(&rawtsvalue(o)->tsv)
155#define rawuvalue(o)	check_exp(ttisuserdata(o), &val_(o).gc->u)
156#define uvalue(o)	(&rawuvalue(o)->uv)
157#define clvalue(o)	check_exp(ttisclosure(o), &val_(o).gc->cl)
158#define clLvalue(o)	check_exp(ttisLclosure(o), &val_(o).gc->cl.l)
159#define clCvalue(o)	check_exp(ttisCclosure(o), &val_(o).gc->cl.c)
160#define fvalue(o)	check_exp(ttislcf(o), val_(o).f)
161#define hvalue(o)	check_exp(ttistable(o), &val_(o).gc->h)
162#define bvalue(o)	check_exp(ttisboolean(o), val_(o).b)
163#define thvalue(o)	check_exp(ttisthread(o), &val_(o).gc->th)
164/* a dead value may get the 'gc' field, but cannot access its contents */
165#define deadvalue(o)	check_exp(ttisdeadkey(o), cast(void *, val_(o).gc))
166
167#define l_isfalse(o)	(ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
168
169
170#define iscollectable(o)	(rttype(o) & BIT_ISCOLLECTABLE)
171
172
173/* Macros for internal tests */
174#define righttt(obj)		(ttype(obj) == gcvalue(obj)->gch.tt)
175
176#define checkliveness(g,obj) \
177	lua_longassert(!iscollectable(obj) || \
178			(righttt(obj) && !isdead(g,gcvalue(obj))))
179
180
181/* Macros to set values */
182#define settt_(o,t)	((o)->tt_=(t))
183
184#define setnvalue(obj,x) \
185  { TValue *io=(obj); num_(io)=(x); settt_(io, LUA_TNUMBER); }
186
187#define setnilvalue(obj) settt_(obj, LUA_TNIL)
188
189#define setfvalue(obj,x) \
190  { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); }
191
192#define setpvalue(obj,x) \
193  { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); }
194
195#define setbvalue(obj,x) \
196  { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); }
197
198#define setgcovalue(L,obj,x) \
199  { TValue *io=(obj); GCObject *i_g=(x); \
200    val_(io).gc=i_g; settt_(io, ctb(gch(i_g)->tt)); }
201
202#define setsvalue(L,obj,x) \
203  { TValue *io=(obj); \
204    TString *x_ = (x); \
205    val_(io).gc=cast(GCObject *, x_); settt_(io, ctb(x_->tsv.tt)); \
206    checkliveness(G(L),io); }
207
208#define setuvalue(L,obj,x) \
209  { TValue *io=(obj); \
210    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TUSERDATA)); \
211    checkliveness(G(L),io); }
212
213#define setthvalue(L,obj,x) \
214  { TValue *io=(obj); \
215    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TTHREAD)); \
216    checkliveness(G(L),io); }
217
218#define setclLvalue(L,obj,x) \
219  { TValue *io=(obj); \
220    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TLCL)); \
221    checkliveness(G(L),io); }
222
223#define setclCvalue(L,obj,x) \
224  { TValue *io=(obj); \
225    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TCCL)); \
226    checkliveness(G(L),io); }
227
228#define sethvalue(L,obj,x) \
229  { TValue *io=(obj); \
230    val_(io).gc=cast(GCObject *, (x)); settt_(io, ctb(LUA_TTABLE)); \
231    checkliveness(G(L),io); }
232
233#define setdeadvalue(obj)	settt_(obj, LUA_TDEADKEY)
234
235
236
237#define setobj(L,obj1,obj2) \
238	{ const TValue *io2=(obj2); TValue *io1=(obj1); \
239	  io1->value_ = io2->value_; io1->tt_ = io2->tt_; \
240	  checkliveness(G(L),io1); }
241
242
243/*
244** different types of assignments, according to destination
245*/
246
247/* from stack to (same) stack */
248#define setobjs2s	setobj
249/* to stack (not from same stack) */
250#define setobj2s	setobj
251#define setsvalue2s	setsvalue
252#define sethvalue2s	sethvalue
253#define setptvalue2s	setptvalue
254/* from table to same table */
255#define setobjt2t	setobj
256/* to table */
257#define setobj2t	setobj
258/* to new object */
259#define setobj2n	setobj
260#define setsvalue2n	setsvalue
261
262
263/* check whether a number is valid (useful only for NaN trick) */
264#define luai_checknum(L,o,c)	{ /* empty */ }
265
266
267/*
268** {======================================================
269** NaN Trick
270** =======================================================
271*/
272#if defined(LUA_NANTRICK)
273
274/*
275** numbers are represented in the 'd_' field. All other values have the
276** value (NNMARK | tag) in 'tt__'. A number with such pattern would be
277** a "signaled NaN", which is never generated by regular operations by
278** the CPU (nor by 'strtod')
279*/
280
281/* allows for external implementation for part of the trick */
282#if !defined(NNMARK)	/* { */
283
284
285#if !defined(LUA_IEEEENDIAN)
286#error option 'LUA_NANTRICK' needs 'LUA_IEEEENDIAN'
287#endif
288
289
290#define NNMARK		0x7FF7A500
291#define NNMASK		0x7FFFFF00
292
293#undef TValuefields
294#undef NILCONSTANT
295
296#if (LUA_IEEEENDIAN == 0)	/* { */
297
298/* little endian */
299#define TValuefields  \
300	union { struct { Value v__; int tt__; } i; double d__; } u
301#define NILCONSTANT	{{{NULL}, tag2tt(LUA_TNIL)}}
302/* field-access macros */
303#define v_(o)		((o)->u.i.v__)
304#define d_(o)		((o)->u.d__)
305#define tt_(o)		((o)->u.i.tt__)
306
307#else				/* }{ */
308
309/* big endian */
310#define TValuefields  \
311	union { struct { int tt__; Value v__; } i; double d__; } u
312#define NILCONSTANT	{{tag2tt(LUA_TNIL), {NULL}}}
313/* field-access macros */
314#define v_(o)		((o)->u.i.v__)
315#define d_(o)		((o)->u.d__)
316#define tt_(o)		((o)->u.i.tt__)
317
318#endif				/* } */
319
320#endif			/* } */
321
322
323/* correspondence with standard representation */
324#undef val_
325#define val_(o)		v_(o)
326#undef num_
327#define num_(o)		d_(o)
328
329
330#undef numfield
331#define numfield	/* no such field; numbers are the entire struct */
332
333/* basic check to distinguish numbers from non-numbers */
334#undef ttisnumber
335#define ttisnumber(o)	((tt_(o) & NNMASK) != NNMARK)
336
337#define tag2tt(t)	(NNMARK | (t))
338
339#undef rttype
340#define rttype(o)	(ttisnumber(o) ? LUA_TNUMBER : tt_(o) & 0xff)
341
342#undef settt_
343#define settt_(o,t)	(tt_(o) = tag2tt(t))
344
345#undef setnvalue
346#define setnvalue(obj,x) \
347	{ TValue *io_=(obj); num_(io_)=(x); lua_assert(ttisnumber(io_)); }
348
349#undef setobj
350#define setobj(L,obj1,obj2) \
351	{ const TValue *o2_=(obj2); TValue *o1_=(obj1); \
352	  o1_->u = o2_->u; \
353	  checkliveness(G(L),o1_); }
354
355
356/*
357** these redefinitions are not mandatory, but these forms are more efficient
358*/
359
360#undef checktag
361#undef checktype
362#define checktag(o,t)	(tt_(o) == tag2tt(t))
363#define checktype(o,t)	(ctb(tt_(o) | VARBITS) == ctb(tag2tt(t) | VARBITS))
364
365#undef ttisequal
366#define ttisequal(o1,o2)  \
367	(ttisnumber(o1) ? ttisnumber(o2) : (tt_(o1) == tt_(o2)))
368
369
370#undef luai_checknum
371#define luai_checknum(L,o,c)	{ if (!ttisnumber(o)) c; }
372
373#endif
374/* }====================================================== */
375
376
377
378/*
379** {======================================================
380** types and prototypes
381** =======================================================
382*/
383
384
385union Value {
386  GCObject *gc;    /* collectable objects */
387  void *p;         /* light userdata */
388  int b;           /* booleans */
389  lua_CFunction f; /* light C functions */
390  numfield         /* numbers */
391};
392
393
394struct lua_TValue {
395  TValuefields;
396};
397
398
399typedef TValue *StkId;  /* index to stack elements */
400
401
402
403
404/*
405** Header for string value; string bytes follow the end of this structure
406*/
407typedef union TString {
408  L_Umaxalign dummy;  /* ensures maximum alignment for strings */
409  struct {
410    CommonHeader;
411    lu_byte extra;  /* reserved words for short strings; "has hash" for longs */
412    unsigned int hash;
413    size_t len;  /* number of characters in string */
414  } tsv;
415} TString;
416
417
418/* get the actual string (array of bytes) from a TString */
419#define getstr(ts)	cast(const char *, (ts) + 1)
420
421/* get the actual string (array of bytes) from a Lua value */
422#define svalue(o)       getstr(rawtsvalue(o))
423
424
425/*
426** Header for userdata; memory area follows the end of this structure
427*/
428typedef union Udata {
429  L_Umaxalign dummy;  /* ensures maximum alignment for `local' udata */
430  struct {
431    CommonHeader;
432    struct Table *metatable;
433    struct Table *env;
434    size_t len;  /* number of bytes */
435  } uv;
436} Udata;
437
438
439
440/*
441** Description of an upvalue for function prototypes
442*/
443typedef struct Upvaldesc {
444  TString *name;  /* upvalue name (for debug information) */
445  lu_byte instack;  /* whether it is in stack */
446  lu_byte idx;  /* index of upvalue (in stack or in outer function's list) */
447} Upvaldesc;
448
449
450/*
451** Description of a local variable for function prototypes
452** (used for debug information)
453*/
454typedef struct LocVar {
455  TString *varname;
456  int startpc;  /* first point where variable is active */
457  int endpc;    /* first point where variable is dead */
458} LocVar;
459
460
461/*
462** Function Prototypes
463*/
464typedef struct Proto {
465  CommonHeader;
466  TValue *k;  /* constants used by the function */
467  Instruction *code;
468  struct Proto **p;  /* functions defined inside the function */
469  int *lineinfo;  /* map from opcodes to source lines (debug information) */
470  LocVar *locvars;  /* information about local variables (debug information) */
471  Upvaldesc *upvalues;  /* upvalue information */
472  union Closure *cache;  /* last created closure with this prototype */
473  TString  *source;  /* used for debug information */
474  int sizeupvalues;  /* size of 'upvalues' */
475  int sizek;  /* size of `k' */
476  int sizecode;
477  int sizelineinfo;
478  int sizep;  /* size of `p' */
479  int sizelocvars;
480  int linedefined;
481  int lastlinedefined;
482  GCObject *gclist;
483  lu_byte numparams;  /* number of fixed parameters */
484  lu_byte is_vararg;
485  lu_byte maxstacksize;  /* maximum stack used by this function */
486} Proto;
487
488
489
490/*
491** Lua Upvalues
492*/
493typedef struct UpVal {
494  CommonHeader;
495  TValue *v;  /* points to stack or to its own value */
496  union {
497    TValue value;  /* the value (when closed) */
498    struct {  /* double linked list (when open) */
499      struct UpVal *prev;
500      struct UpVal *next;
501    } l;
502  } u;
503} UpVal;
504
505
506/*
507** Closures
508*/
509
510#define ClosureHeader \
511	CommonHeader; lu_byte nupvalues; GCObject *gclist
512
513typedef struct CClosure {
514  ClosureHeader;
515  lua_CFunction f;
516  TValue upvalue[];  /* list of upvalues */
517} CClosure;
518
519
520typedef struct LClosure {
521  ClosureHeader;
522  struct Proto *p;
523  UpVal *upvals[];  /* list of upvalues */
524} LClosure;
525
526
527typedef union Closure {
528  CClosure c;
529  LClosure l;
530} Closure;
531
532
533#define isLfunction(o)	ttisLclosure(o)
534
535#define getproto(o)	(clLvalue(o)->p)
536
537
538/*
539** Tables
540*/
541
542typedef union TKey {
543  struct {
544    TValuefields;
545    struct Node *next;  /* for chaining */
546  } nk;
547  TValue tvk;
548} TKey;
549
550
551typedef struct Node {
552  TValue i_val;
553  TKey i_key;
554} Node;
555
556
557typedef struct Table {
558  CommonHeader;
559  lu_byte flags;  /* 1<<p means tagmethod(p) is not present */
560  lu_byte lsizenode;  /* log2 of size of `node' array */
561  int sizearray;  /* size of `array' array */
562  TValue *array;  /* array part */
563  Node *node;
564  Node *lastfree;  /* any free position is before this position */
565  struct Table *metatable;
566  GCObject *gclist;
567} Table;
568
569
570
571/*
572** `module' operation for hashing (size is always a power of 2)
573*/
574#define lmod(s,size) \
575	(check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1)))))
576
577
578#define twoto(x)	(1<<(x))
579#define sizenode(t)	(twoto((t)->lsizenode))
580
581
582/*
583** (address of) a fixed nil value
584*/
585#define luaO_nilobject		(&luaO_nilobject_)
586
587
588LUAI_DDEC const TValue luaO_nilobject_;
589
590
591LUAI_FUNC int luaO_int2fb (unsigned int x);
592LUAI_FUNC int luaO_fb2int (int x);
593LUAI_FUNC int luaO_ceillog2 (unsigned int x);
594LUAI_FUNC lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2);
595LUAI_FUNC int luaO_str2d (const char *s, size_t len, lua_Number *result);
596LUAI_FUNC int luaO_hexavalue (int c);
597LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
598                                                       va_list argp);
599LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
600LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
601
602
603#endif
604